Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

There is a place where if I stand up straight, I will still be considered sideways.

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

Before Mount Everest was discovered, what was the highest mountain in the world?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

The following "Brain Bat" means Slow Down.
S
L
O
W

Using the same logic, can you tell us what does the following Brain Bat means ?
E
V
I
G

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?